123-453: Parasuchia Huxley , 1875 Phytosaurs (Φυτόσαυροι in Greek , meaning 'plant lizard') are an extinct group of large, mostly semiaquatic Late Triassic archosauriform reptiles. Phytosaurs belong to the order Phytosauria and are sometimes referred to as parasuchians . Phytosauria, Parasuchia, Parasuchidae, and Phytosauridae have often been considered equivalent groupings containing
246-401: A "death roll", spinning or convulsing wildly until bite-sized chunks are torn off. Critical to the alligator's ability to initiate a death roll, the tail must flex to a significant angle relative to its body. An alligator with an immobilized tail cannot perform a death roll. Most of the muscle in an alligator's jaw evolved to bite and grip prey. The muscles that close the jaws are powerful, but
369-458: A 2001 study of the biomechanics of the dinosaur Albertosaurus 's teeth, William L. Abler also examined a phytosaur's teeth, finding that it has had serrations so fine that they resembled a crack in the tooth. Albertosaurus had similarly crack-like serrations, but, at the base of each serration Abler discovered a round void , which would have functioned to distribute force over a larger surface area . This void, termed an ampulla, would hinder
492-406: A Louisiana swamp in 1987. Alligators are raised commercially for their meat and their skin, which when tanned is used for the manufacture of luggage , handbags , shoes, belts , and other leather items. Alligators also provide economic benefits through the ecotourism industry. Visitors may take swamp tours, in which alligators are a feature. Their most important economic benefit to humans may be
615-451: A breeding pair of Chinese alligators. Large male alligators are solitary territorial animals. Smaller alligators can often be found in large numbers close to each other. The largest of the species (both males and females) defend prime territory; smaller alligators have a higher tolerance for other alligators within a similar size class. Alligators move on land by two forms of locomotion, referred to as "sprawl" and "high walk". The sprawl
738-537: A combination of the two. However, two taxa show slight adaptations towards hunting and consuming harder invertebrates. A study on phytosaur microwear patterns has found Mystriosuchus to line with soft invertebrate consumers, Nicrosaurus with hard invertebrate consumers and Smilosuchus and Machaeroprosopus with carnivores and piscivores. Phytosaurs have been traditionally held as rather "primitive" animals in regards to terrestrial locomotion, particularly in regards to archosaurs such as crocodilians , lacking
861-409: A detailed account for Darwin, a letter which does not survive; however, a letter to his friend Frederick Daniel Dyster does survive with an account just three months after the event. One effect of the debate was to hugely increase Huxley's visibility amongst educated people, through the accounts in newspapers and periodicals. Another consequence was to alert him to the importance of public debate:
984-633: A distinct group of taxa (named Mystriosuchinae of Friedrich von Huene ) as other morphotypes such as Pseudopalatus are more closely related to Mystriosuchus than it is to the other long-snouted taxa. Brachyrostral ("short snouted") forms are the opposite, having a massive, broad snout, and very strong skulls and jaws. They are heterodont , as the front teeth are prominent fangs, and the rear teeth are blade-like for slicing food into chunks that can be swallowed easily. Taxa like this, such as Nicrosaurus and Smilosuchus , were powerful taxa that fed on stronger prey, such as terrestrial animals that came to
1107-478: A hypothesis which was a good working basis. Logically speaking, the prior question was whether evolution had taken place at all. It is to this question that much of Darwin's On the Origin of Species was devoted. Its publication in 1859 completely convinced Huxley of evolution and it was this and no doubt his admiration of Darwin's way of amassing and using evidence that formed the basis of his support for Darwin in
1230-497: A length of 1.8 m (6 ft). The mating season is in late spring. In April and May, alligators form so-called "bellowing choruses". Large groups of animals bellow together for a few minutes a few times a day, usually one to three hours after sunrise. The bellows of male American alligators are accompanied by powerful blasts of infrasound . Another form of male display is a loud head-slap. In 2010, on spring nights alligators were found to gather in large numbers for group courtship,
1353-416: A lesson he never forgot. A third effect was to serve notice that Darwinian ideas could not be easily dismissed: on the contrary, they would be vigorously defended against orthodox authority. A fourth effect was to promote professionalism in science, with its implied need for scientific education. A fifth consequence was indirect: as Wilberforce had feared, a defence of evolution did undermine literal belief in
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#17327754884291476-439: A meal by up to four times its basal metabolic rate. Alligators also have highly folded mucosa in the lining of the intestines to further aid in the absorption of nutrients. The folds result in greater surface area for the nutrients to be absorbed through. Alligators also have complex microbiomes that are not fully understood yet, but can be attributed to both benefits and costs to the animal. These microorganisms can be found in
1599-557: A meal during brumation will begin a process called autophagy , where the animal begins to consume its fat reserves to maintain its body weight until it can acquire a sufficient meal. There is also fluctuation in the level of bacterial taxa populations in the alligator's microbial community between seasons which helps the alligator cope with different rates of feeding and activity. Like other crocodilians, alligators have an armor of bony scutes. The dermal bones are highly vascularised and aid in calcium balance, both to neutralize acids while
1722-524: A nominal assistant-surgeon, so he might work on the specimens he collected and the observations he made during the voyage of the Rattlesnake . He solved the problem of Appendicularia , whose place in the animal kingdom Johannes Peter Müller had found himself wholly unable to assign. It and the Ascidians are both, as Huxley showed, tunicates , today regarded as a sister group to the vertebrates in
1845-657: A palaeontologist is marked by a rather strange predilection for 'persistent types', in which he seemed to argue that evolutionary advancement (in the sense of major new groups of animals and plants) was rare or absent in the Phanerozoic . In the same vein, he tended to push the origin of major groups such as birds and mammals back into the Palaeozoic era, and to claim that no order of plants had ever gone extinct. Much paper has been consumed by historians of science ruminating on this strange and somewhat unclear idea. Huxley
1968-506: A recent study has suggested that Diandongosuchus is a basal phytosaur. If this is the case, this taxon offers more of a bridge between phytosaurs and earlier Archosauriformes. The earliest phytosaurs are traditionally classified in the genus Paleorhinus , now thought to be polyphyletic . Parasuchus and related basal species were widely distributed, meaning that phytosaurs dispersed across Pangea early on and there were probably few geographical barriers for their distribution; only in
2091-457: A remarkable resemblance to modern crocodilians in size, appearance, and lifestyle, as an example of convergence or parallel evolution . The name "phytosaur" means "plant lizard", as the first fossils of phytosaurs were mistakenly thought to belong to plant eaters. For many years, phytosaurs were considered to be the most basal group of Pseudosuchia (crocodile-line archosaurs ), meaning that they were thought to be more closely related to
2214-407: A secondarily terrestrial lifestyle, developing longer limb bones, straighter femora and a deeper pelvis, and indeed occurs in terrestrial or marginal lacustrine settings. Combined with its deep upper jaw, it probably led a similar lifestyle to terrestrial predatory crocodylomorphs like sebecians . Inversely, some dolichorostral forms like Mystriosuchus have become further specialised to life in
2337-497: A silver medal prize in the Apothecaries' yearly competition, Huxley was admitted to study at Charing Cross Hospital , where he obtained a small scholarship. At Charing Cross, he was taught by Thomas Wharton Jones , Professor of Ophthalmic Medicine and Surgery at University College London . Jones had been Robert Knox 's assistant when Knox bought cadavers from Burke and Hare . The young Wharton Jones, who acted as go-between,
2460-643: A street in the Bronx , New York was named in his honor (Huxley Avenue). As recognition of his many public services, he was appointed Privy Councillor in 1892. Despite his many achievements, he was given no award by the British state until late in life. In this, he did better than Darwin, who got no award of any kind from the state. (Darwin's proposed knighthood was vetoed by ecclesiastical advisers, including Wilberforce.) Perhaps Huxley had commented too often on his dislike of honours, or perhaps his many assaults on
2583-594: A track record against evolution as far back as the previous Oxford B.A. meeting in 1847 when he attacked Chambers' Vestiges . For the more challenging task of opposing the Origin , and the implication that man descended from apes, he had been assiduously coached by Richard Owen —Owen stayed with him the night before the debate. On the day, Wilberforce repeated some of the arguments from his Quarterly Review article (written but not yet published), then ventured onto slippery ground. His famous jibe at Huxley (as to whether Huxley
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#17327754884292706-514: A view now held by modern biologists. The tendency has been for this fine anatomical work to be overshadowed by his energetic and controversial activity in favour of evolution, and by his extensive public work on scientific education, both of which had significant effects on society in Britain and elsewhere. Huxley's 1893 Romanes Lecture , "Evolution and Ethics", is exceedingly influential in China;
2829-787: Is 360 kg (790 lb) and 4 m (13 ft), but they sometimes grow to 4.4 m (14 ft) long and weigh over 450 kg (990 lb). The largest ever recorded, found in Louisiana, measured 5.84 m (19.2 ft). The Chinese alligator is smaller, rarely exceeding 2.1 m (7 ft) in length. Additionally, it weighs considerably less, with males rarely over 45 kg (100 lb). Adult alligators are black or dark olive-brown with white undersides, while juveniles have bright yellow or whitish stripes which sharply contrast against their dark hides, providing them additional camouflage amongst reeds and wetland grasses. No average lifespan for an alligator has been measured. One of
2952-469: Is a forward movement with the belly making contact with the ground and is used to transition to "high walk" or to slither over wet substrate into water. The high walk is an up-on-four-limbs forward motion used for overland travel with the belly well up from the ground. Alligators have also been observed to rise up and balance on their hind legs and semi-step forward as part of a forward or upward lunge. However, they can not walk on their hind legs. Although
3075-540: Is a large reptile in the genus Alligator of the family Alligatoridae of the order Crocodilia . The two extant species are the American alligator ( A. mississippiensis ) and the Chinese alligator ( A. sinensis ). Additionally, several extinct species of alligator are known from fossil remains. Alligators first appeared during the late Eocene epoch about 37 million years ago. The name "alligator"
3198-407: Is attached to the shoulder or pelvis by a single bone, the humerus or femur. His interest in these fish brought him close to the origin of tetrapods , one of the most important areas of vertebrate palaeontology. The study of fossil reptiles led to his demonstrating the fundamental affinity of birds and reptiles, which he united under the title of Sauropsida . His papers on Archaeopteryx and
3321-517: Is found in only the Yangtze River valley and parts of adjacent provinces and is extremely endangered, with only a few dozen believed to be left in the wild. Far more Chinese alligators live in zoos around the world than can be found in the wild. Rockefeller Wildlife Refuge in southern Louisiana has several in captivity in an attempt to preserve the species. Miami MetroZoo in Florida also has
3444-598: Is likely an anglicized form of el lagarto , the Spanish term for "the lizard", which early Spanish explorers and settlers in Florida called the alligator. Early English spellings of the name included allagarta and alagarto . Alligators and caimans split in North America during the early Tertiary or late Cretaceous (about 53 million to about 65 million years ago). The Chinese alligator split from
3567-617: Is not known if this is truly a member of the clade. Phytosaurs are known from many different morphologies, specifically with vastly different skull forms. These changes relate to the feeding and habits of the animals, not completely evolutionary modifications. Dolichorostral ("long snouted") phytosaurs have a long, slender snout with many conical teeth that are homodont (all the same). These taxa were most likely piscivores that were well adapted to capture fast aquatic prey, but not terrestrial animals. Paleorhinus , Rutiodon and Mystriosuchus are dolichorostral phytosaurs, but do not form
3690-521: Is reprobated as "utterly dishonourable to Natural Science." If I confine my retrospect of the reception of the Origin of Species to a twelvemonth, or thereabouts, from the time of its publication, I do not recollect anything quite so foolish and unmannerly as the Quarterly Review article... Since his death, Huxley has become known as "Darwin's Bulldog", taken to refer to his pluck and courage in debate, and to his perceived role in protecting
3813-489: Is the standard generic name for these animals, despite the fact that these animals have been clearly shown to be carnivorous . Phytosaurs first appeared during the Carnian or Ladinian age, evolving from an unknown crurotarsan ancestor. There are no clear intermediate forms, as even the earliest known phytosaurs are highly specialized aquatic animals, unlike most contemporary archosauriforms that were terrestrial. However,
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3936-548: The Quarterly Review , running to 17,000 words. The authorship of this latter review was not known for sure until Wilberforce's son wrote his biography. So it can be said that, just as Darwin groomed Huxley, so Owen groomed Wilberforce; and both the proxies fought public battles on behalf of their principals as much as themselves. Though we do not know the exact words of the Oxford debate, we do know what Huxley thought of
4059-634: The American alligator about 33 million years ago and probably descended from a lineage that crossed the Bering land bridge during the Neogene . The modern American alligator is well represented in the fossil record of the Pleistocene . The alligator's full mitochondrial genome was sequenced in the 1990s. The full genome , published in 2014, suggests that the alligator evolved much more slowly than mammals and birds. The genus Alligator belongs to
4182-544: The Chinle Formation , but these "nests" are apparently the result of sandstone weathering. A recent study suggests they might have had parental care. When the first phytosaur fossils were found, it was not immediately obvious what kind of animal/species they were. The first phytosaur species known to science was named Phytosaurus cylindricodon – "plant lizard with cylindrical teeth" – by G. Jaeger in 1828 because he mistakenly believed that petrified mud fillings in
4305-915: The Copley Medal in 1888 and the Darwin Medal in 1894; the Geological Society awarded him the Wollaston Medal in 1876; the Linnean Society awarded him the Linnean Medal in 1890. There were many other elections and appointments to eminent scientific bodies; these and his many academic awards are listed in the Life and Letters . He turned down many other appointments, notably the Linacre chair in zoology at Oxford and
4428-530: The Old Testament , especially the Book of Genesis . Many of the liberal clergy at the meeting were quite pleased with the outcome of the debate; they were supporters, perhaps, of the controversial Essays and Reviews . Thus, both on the side of science and on that of religion, the debate was important and its outcome significant. (see also below ) Alligator An alligator , or colloquially gator ,
4551-604: The University of London , winning the gold medal for anatomy and physiology . However, he did not present himself for the final (Second M.B.) exams and consequently did not qualify for a university degree. His apprenticeships and exam results formed a sufficient basis for his application to the Royal Navy . Aged 20, Huxley was too young to apply to the Royal College of Surgeons for a licence to practise, yet he
4674-419: The apex predator throughout their distribution. In this role as a top predator, it may determine the abundance of prey species, including turtles and nutrias. As humans encroach into their habitat, attacks are few but not unknown. Alligators, unlike the large crocodiles , do not immediately regard a human upon encounter as prey, but may still attack in self-defense if provoked. Alligators generally mature at
4797-484: The crocodile , with minor differences in morphology and enzyme activity. Alligators have a two-part stomach, with the first smaller portion containing gastroliths . It is believed this portion of the stomach serves a similar function as it does in the gizzard of some species of birds, to aid in digestion. The gastroliths work to grind up the meal as alligators will take large bites or swallow smaller prey whole. This process makes digestion and nutrient absorption easier once
4920-456: The end Triassic extinction event , about 200 Ma ago. There have been reports of phytosaur remains found in lowermost Jurassic rocks. Several teeth from Early Jurassic deposits in France have been identified as phytosaur teeth, but other studies argue they have either been misidentified or were reworked from Late Triassic into Early Jurassic deposits. In 1951, a partial upper jaw was discovered in
5043-491: The evolution of the horse has many other members, and the overall appearance of the tree of descent is more like a bush than a straight line. The horse series also strongly suggested that the process was gradual, and that the origin of the modern horse lay in North America, not in Eurasia. If so, then something must have happened to horses in North America, since none were there when Europeans arrived. The experience with Marsh
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5166-457: The origin of birds were of great interest then and still are. Apart from his interest in persuading the world that man was a primate and had descended from the same stock as the apes, Huxley did little work on mammals, with one exception. On his tour of America Huxley was shown the remarkable series of fossil horses, discovered by O. C. Marsh , in Yale 's Peabody Museum . An Easterner, Marsh
5289-816: The subfamily Alligatorinae , which is the sister taxon to Caimaninae (the caimans ). Together, these two subfamilies form the family Alligatoridae . The cladogram below shows the phylogeny of alligators. Caimaninae Ceratosuchus burdoshi † Hassiacosuchus haupti † Navajosuchus mooki † Wannaganosuchus brachymanus † Arambourgia gaudryi † Allognathosuchus polyodon † Allognathosuchus wartheni † Procaimanoidea kayi † Alligator prenasalis † Alligator mcgrewi † Alligator olseni † Alligator sinensis Chinese alligator Alligator thomsoni † Alligator mefferdi † Alligator mississippiensis American alligator An average adult American alligator's weight and length
5412-923: The Advancement of Science 1869–1870; president of the Quekett Microscopical Club 1878; president of the Royal Society 1883–1885; Inspector of Fisheries 1881–1885; and president of the Marine Biological Association 1884–1890. He was elected as a member to the American Philosophical Society in 1869. The thirty-one years during which Huxley occupied the chair of natural history at the Royal School of Mines included work on vertebrate palaeontology and on many projects to advance
5535-624: The Chinese translation of Huxley's lecture even transformed the Chinese translation of Darwin's Origin of Species . Thomas Henry Huxley was born in Ealing , then a village in Middlesex . He was the second youngest of eight children of George Huxley and Rachel Withers. His parents were members of the Church of England, but he sympathized with nonconformists . Like some other British scientists of
5658-539: The Early Norian sees new genera like Nicrosaurus and Pseudopalatus , both of which belong to the most derived clade of phytosaurs, the Pseudopalatinae . Later in the middle Norian the advanced and specialised fish-eater Mystriosuchus appears. Fossil remains of this widespread animal is known from Germany, northern Italy, and Thailand. Finally the large Redondasaurus in southwest North America and
5781-646: The Early Jurassic Lower Lufeng Series in China and described as a new genus of phytosaur, Pachysuchus , but a study in 2012 reinterpreted the fossil as a sauropodomorph dinosaur. A fragment of a lower jaw from a longirostrine archosaur has been described from early Hettangian strata in the town of Watchet in Somerset , England. While teleosaurid thalattosuchians had similar longirostrine jaws to phytosaurs and were common in
5904-467: The Jurassic, they do not appear in the earliest Jurassic rocks. The mandible is more similar to those of known phytosaurs than to thalattosuchians, and likely belongs to a phytosaur closely related to the genus Mystriosuchus . The presence of phytosaurs in the earliest Jurassic may have prevented thalattosuchians from occupying similar ecological niches at that time. However, more recent work suggests that
6027-751: The Mastership of University College, Oxford . In 1873 the King of Sweden made Huxley, Hooker and Tyndall Knights of the Order of the Polar Star : they could wear the insignia but not use the title in Britain. Huxley collected many honorary memberships of foreign societies, academic awards and honorary doctorates from Britain and Germany. He also became a foreign member of the Royal Netherlands Academy of Arts and Sciences in 1892. In 1916,
6150-543: The Natural History of Creation , a book which contained some quite pertinent arguments in favour of evolution. Huxley had also rejected Lamarck's theory of transmutation, on the basis that there was insufficient evidence to support it. All this scepticism was brought together in a lecture to the Royal Institution, which made Darwin anxious enough to set about an effort to change young Huxley's mind. It
6273-590: The Royal Society, persuaded government about science, and established scientific education in British schools and universities. He was awarded the highest honours then open to British men of science. The Royal Society , who had elected him as Fellow when he was 25 (1851), awarded him the Royal Medal the next year (1852), a year before Charles Darwin got the same award. He was the youngest biologist to receive such recognition. Then later in life he received
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#17327754884296396-685: The Triassic. Fossils have been recovered from Europe , North America , India , Morocco , Thailand , Brazil , Greenland and Madagascar . Fossils attributed to phytosaurs have been found in Early Jurassic rocks, possibly extending their temporal range beyond the Triassic-Jurassic boundary. They may have also been present in rock layers dating to the Middle Triassic of China as evidenced by Diandongosuchus , however it
6519-409: The ability of the "crack" formed by the serration to propagate through the tooth. The phytosaur was found to lack adaptations for preventing its dental "cracks" from propagating. Abler examined another sort of prehistoric predator, Dimetrodon , and found that it also lacked adaptations for guarding against crack propagation. Based on their teeth, most phytosaur genera are carnivorous, piscivorous, or
6642-406: The alligator has a heavy body and a slow metabolism , it is capable of short bursts of speed, especially in very short lunges. Alligators' main prey are smaller animals they can kill and eat with a single bite. They may kill larger prey by grabbing it and dragging it into the water to drown. Alligators consume food that cannot be eaten in one bite by allowing it to rot or by biting and then performing
6765-547: The animal cannot breathe underwater and to provide calcium for eggshell formation. Alligators have muscular, flat tails that propel them while swimming. The two kinds of white alligators are albino and leucistic . These alligators are practically impossible to find in the wild. They could survive only in captivity and are few in number. The Aquarium of the Americas in New Orleans has leucistic alligators found in
6888-781: The animals into attacking. In Florida, feeding wild alligators at any time is illegal. If fed, the alligators will eventually lose their fear of humans and will learn to associate humans with food. The type of food eaten by alligators depends upon their age and size. When young, alligators eat fish, insects, snails , crustaceans , and worms . As they mature, progressively larger prey is taken, including larger fish such as gar , turtles, and various mammals, particularly nutrias and muskrats, as well as birds, deer, and other reptiles. Their stomachs also often contain gizzard stones . They will even consume carrion if they are sufficiently hungry. In some cases, larger alligators are known to ambush dogs, Florida panthers and black bears , making them
7011-421: The belly reinforced with a dense arrangement of gastralia (abdominal ribs). Finally, and most noticeably, phytosaurs had nostrils placed near or above the level of the eyes, in contrast to crocodiles where the nostrils are near the end of the snout. This adaptation may have developed to allow them to breathe while the rest of the body was submerged. Unlike most crocodilians, phytosaurs have tooth serrations. In
7134-511: The crocodiles", as they resembled crocodiles to a great degree) was coined by Thomas Huxley in 1875 along with his discovery and naming of the Indian species Parasuchus hislopi (Chatterjee, 1978), on the basis of a partial snout. The specimen also is usually considered non-diagnostic, and the name Parasuchus replaced by Paleorhinus . Although the names Parasuchidae and Phytosauridae are variously still used by different specialists, "phytosaur"
7257-426: The crocodilians than to birds (the other living group of archosaurs). Some studies of the evolutionary relationships of early archosauriforms have suggested that phytosaurs evolved before the split between crocodile- and bird-line archosaurs and are a sister taxon of Archosauria. The most recent study retains the former way of classifying phytosaurs as pseudosuchians. Phytosaurs had a nearly global distribution during
7380-408: The death of his eldest son Noel, who died of scarlet fever in 1860; Huxley's wife Henrietta Anne née Heathorn and son Noel are also buried there. Huxley and his wife had five daughters and three sons: From 1870 onwards, Huxley was to some extent drawn away from scientific research by the claims of public duty. He served on eight Royal Commissions , from 1862 to 1884. From 1871 to 1880 he
7503-621: The debate at the British Association meeting, on Saturday 30 June 1860 at the Oxford University Museum. Huxley's presence there had been encouraged on the previous evening when he met Robert Chambers, the Scottish publisher and author of Vestiges , who was walking the streets of Oxford in a dispirited state, and begged for assistance. The debate followed the presentation of a paper by John William Draper , and
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#17327754884297626-463: The debate, and written less than a month afterwards. Other eyewitnesses, with one or two exceptions (Hooker especially thought he had made the best points), give similar accounts, at varying dates after the event. The general view was and still is that Huxley got much the better of the exchange, though Wilberforce himself thought he had done quite well. In the absence of a verbatim report, differing perceptions are difficult to judge fairly; Huxley wrote
7749-704: The debates that followed the book's publication. Huxley's support started with his anonymous favourable review of the Origin in the Times for 26 December 1859, and continued with articles in several periodicals, and in a lecture at the Royal Institution in February 1860. At the same time, Richard Owen , whilst writing an extremely hostile anonymous review of the Origin in the Edinburgh Review , also primed Samuel Wilberforce who wrote one in
7872-434: The discipline itself, developed. Huxley's detailed anatomical work was, as always, first-rate and productive. His work on fossil fish shows his distinctive approach: Whereas pre-Darwinian naturalists collected, identified, and classified, Huxley worked mainly to reveal the evolutionary relationships between groups. The lobe-finned fish (such as coelacanths and lungfish ) have paired appendages whose internal skeleton
7995-502: The erect gait seen in these, other pseudosuchians , dinosaurs and pterosaurs . However, the Apatopus ichnofossil shows that the animals did in fact have an erect gait like their archosaur relatives. Most phytosaurs are thought to be aquatic animals, and indeed most do show adaptations for such a lifestyle; swim tracks attributed to phytosaurs, for example, are known. However, at least Nicrosaurus seems to have evolved towards
8118-420: The first time indicated the direct line of descent of an existing animal. With the generosity of true greatness, he gave up his own opinions in the face of new truth, and took my conclusions as the basis of his famous New York lecture on the horse." Huxley was originally not persuaded by "development theory", as evolution was once called. This can be seen in his savage review of Robert Chambers ' Vestiges of
8241-462: The food reaches the second portion of the stomach. Once an alligator's meal has been processed it will move on to the second portion of the stomach which is highly acidic. The acidity of the stomach has been observed to increase once digestion begins. This is due to the increase in CO 2 concentration of the blood, resulting from the right to left shunting of the alligators heart. The right to left shunt of
8364-414: The former tend to produce males and the latter, females. The baby alligator's egg tooth helps it get out of its egg during hatching time. The natural sex ratio at hatching is five females to one male. Females hatched from eggs incubated at 30 °C (86 °F) weigh significantly more than males hatched from eggs incubated at 34 °C (93 °F). The mother defends the nest from predators and assists
8487-421: The hatchlings to water. She will provide protection to the young for about a year if they remain in the area. Adult alligators regularly cannibalize younger individuals, though estimates of the rate of cannibalism vary widely. In the past, immediately following the outlawing of alligator hunting , populations rebounded quickly due to the suppressed number of adults preying upon juveniles, increasing survival among
8610-501: The heart in alligators means the circulatory system will recirculate blood through the body instead of back to the lungs. The re-circulation of blood leads to higher CO 2 concentration as well as lower oxygen affinity. There is evidence to suggest that there is increased blood flow diverted to the stomach during digestion to facilitate an increase in CO 2 concentration which aids in increasing gastric acid secretions during digestion. The alligator's metabolism will also increase after
8733-468: The high surface area of the mucosa folds of the intestines, as well as throughout the digestive tract. Benefits include better total health and stronger immune system. However alligators are still vulnerable to microbial infections despite the immune boost from other microbiota. During brumation the process of digestion experiences changes due to the fasting most alligators experience during these periods of inactivity. Alligators that go long enough without
8856-469: The horse fossils were really special. After a week with Marsh and his fossils, Huxley wrote excitedly, "The collection of fossils is the most wonderful thing I ever saw." The collection at that time went from the small four-toed forest-dwelling Orohippus from the Eocene through three-toed species such as Miohippus to species more like the modern horse. By looking at their teeth he could see that, as
8979-420: The inspired air must move back out the same way it came in. In contrast, air in alligator lungs makes a circuit, moving in only one direction through the parabronchi . The air first enters the outer branch, moves through the parabronchi, and exits the lung through the inner branch. Oxygen exchange takes place in extensive vasculature around the parabronchi. The alligator has a similar digestive system to that of
9102-1317: The jaw fragment came from a pre-Hettangian rock unit, and is therefore Late Triassic in age. Also, if the age of the Magnesian Conglomerate does extend into the Early Jurassic ( Hettangian ), then it is possible that Rileyasuchus survived into the Early Jurassic. Angistorhinopsis Angistorhinus [REDACTED] Morocco [REDACTED] US Argana Formation Dockum Group Popo Agie Formation Arganarhinus [REDACTED] Morocco Argana Formation Arribasuchus Belodon [REDACTED] Germany [REDACTED] US Stubensandstein Chinle Formation Brachysuchus [REDACTED] US "Pre-Tecovas Horizon" ( Dockum Group ) Centemodon [REDACTED] US Cumnock Formation Coburgosuchus [REDACTED] Germany ? Diandongosuchus [REDACTED] China Falang Formation Ebrachosuchus [REDACTED] Germany Hassberge Formation Thomas Huxley Thomas Henry Huxley (4 May 1825 – 29 June 1895)
9225-478: The jaw were herbivore teeth. The specimen is too poor to be diagnostic, and this species name is no longer valid. The name of the group – Phytosauria – was coined by the German paleontologist Hermann von Meyer in 1861, on the basis of this first species. The next species to be described was Belodon plieningeri by von Meyer in von Meyer and Plieninger 1844. The altogether more appropriate name Parasuchia ("alongside
9348-445: The largest alligator population. The majority of American alligators inhabit Florida and Louisiana, with over a million alligators in each state. Southern Florida is the only place where both alligators and crocodiles live side by side. American alligators live in freshwater environments, such as ponds , marshes , wetlands , rivers , lakes , and swamps , as well as in brackish water . When they construct alligator holes in
9471-448: The long snouted dolichorostral gavial . Various phytosaurs have crests and similar ornamentions in their snouts. Nicrosaurus has a ridge along the snout that would have supported a keratinous crest in life, while Mystriosuchus westphali has several bony crests. Despite their great similarities in appearance and lifestyle, there are still a number of minor differences that distinguish phytosaurs from true crocodiles. For one thing,
9594-692: The long-snouted (altirostral) Angistorhinopsis ruetimeyeri in Europe continued the group into the Rhaetian . Phytosaur footprints (the ichnotaxon Apatopus ) are also known from the latest Rhaetian of the East Coast of USA (the Newark Supergroup ) (Olsen et al. 2002). This indicates that phytosaurs continued as successful animals until the very end of the Triassic, when, along with many other large crurotarsan reptiles, they were killed off by
9717-437: The muscles for opening their jaws are weak. As a result, an adult human can hold an alligator's jaws shut bare-handed. It is common to use several wraps of duct tape to prevent an adult alligator from opening its jaws when being handled or transported. Alligators are generally timid towards humans and tend to walk or swim away if one approaches. This may encourage people to approach alligators and their nests, which can provoke
9840-454: The name of Hydrozoa . The connection he made was that all the members of the class consisted of two cell layers, enclosing a central cavity or stomach. This is characteristic of the phylum now called the Cnidaria . He compared this feature to the serous and mucous structures of embryos of higher animals. When at last he got a grant from the Royal Society for the printing of plates, Huxley
9963-598: The navy by refusing to return to active service, and in July 1854 he became professor of natural history at the Royal School of Mines and naturalist to the British Geological Survey in the following year. In addition, he was Fullerian Professor at the Royal Institution 1855–1858 and 1865–1867; Hunterian Professor at the Royal College of Surgeons 1863–1869; president of the British Association for
10086-412: The nineteenth century such as Alfred Russel Wallace , Huxley was brought up in a literate middle-class family which had fallen on hard times. His father was a mathematics teacher at Great Ealing School until it closed, putting the family into financial difficulties. As a result, Thomas left school at the age of 10, after only two years of formal schooling. Despite this lack of formal schooling, Huxley
10209-466: The older man. The sobriquet appears to be Huxley's own invention, although of unknown date, and it was not current in his lifetime. While the second half of Darwin's life was lived mainly within his family, the younger and combative Huxley operated mainly out in the world at large. A letter from Huxley to Ernst Haeckel (2 November 1871) states: "The dogs have been snapping at [Darwin's] heels too much of late." Famously, Huxley responded to Wilberforce in
10332-807: The oldest recorded alligator lives was that of Saturn , an American alligator who was hatched in 1936 in Mississippi and spent nearly a decade in Germany before spending the majority of his life at the Moscow Zoo , where he died at the age of 83 or 84 on 22 May 2020. Another one of the oldest lives on record is that of Muja , an American alligator who was brought as an adult specimen to the Belgrade Zoo in Serbia from Germany in 1937. Although no valid records exist about his date of birth, as of 2012, he
10455-661: The original. Later on, as a young adult, he made himself an expert, first teaching himself about invertebrates , and later on vertebrates . He did many of the illustrations for his publications on marine invertebrates. In his later debates and writing on science and religion, his grasp of theology was better than many of his clerical opponents. He was apprenticed for short periods to several medical practitioners: at 13 to his brother-in-law John Cooke in Coventry, who passed him on to Thomas Chandler, notable for his experiments using mesmerism for medical purposes. Chandler's practice
10578-540: The phylum Chordata . Other papers on the morphology of the cephalopods and on brachiopods and rotifers are also noteworthy. Following a lecture at the Royal Institution on 30 April 1852 Huxley indicated that it remained difficult to earn a living as a scientist alone. This was demonstrated in a letter written on 3 May 1852, where he states "Science in England does everything—but PAY. You may earn praise but not pudding". However, Huxley effectively resigned from
10701-437: The phytosaur ankle structure is much more primitive than that of any crocodile. Also, phytosaurs lack the bony secondary palate that enables crocodiles to breathe even when the mouth is full of water. However, it is possible that phytosaurs had a fleshy palate, as many Mesozoic crocodiles are presumed to have had. Phytosaurs were even better armoured than crocodiles, protected by heavy bony scutes (often found as fossils), and
10824-503: The place of science in British life. Huxley retired in 1885, after a bout of depressive illness which started in 1884. He resigned the presidency of the Royal Society in mid-term, the Inspectorship of Fisheries, and his chair (as soon as he decently could) and took six months' leave. His pension was £1200 a year. Huxley's London home, in which he wrote many of his works, was at 4 Marlborough Place , St John's Wood . The house
10947-406: The presence of multiple sinuses, smaller cerebral hemispheres and smaller endosseous labyrinths. The similarities are considered to be plesiomorphic in relation to the ancestral archosauriform design, lacking many features seen in avemetatarsalians , though convergence in terms of lifestyle might also play a role. No phytosaur eggs have been found so far. There are pits associated with footprints in
11070-659: The remains of Pithecanthropus erectus (now known as Homo erectus ). He died of a heart attack (after contracting influenza and pneumonia) in 1895 in Eastbourne, and was buried in London at East Finchley Cemetery . No invitations were sent out but two hundred people turned up for the funeral; they included Joseph Dalton Hooker , William Henry Flower , Mulford B. Foster , Edwin Lankester , Joseph Lister , and apparently Henry James . The family plot had been purchased upon
11193-609: The review in the Quarterly : Since Lord Brougham assailed Dr Young , the world has seen no such specimen of the insolence of a shallow pretender to a Master in Science as this remarkable production, in which one of the most exact of observers, most cautious of reasoners, and most candid of expositors, of this or any other age, is held up to scorn as a "flighty" person, who endeavours "to prop up his utterly rotten fabric of guess and speculation," and whose "mode of dealing with nature"
11316-633: The same species. Some recent studies have offered a more nuanced approach, defining Parasuchidae and Phytosauridae as nested clades within Phytosauria as a whole. The clade Phytosauria was defined by Paul Sereno in 2005 as Rutiodon carolinensis and all taxa more closely related to it than to Aetosaurus ferratus , Rauisuchus tiradentes , Prestosuchus chiniquensis , Ornithosuchus woodwardi , or Crocodylus niloticus (the Nile crocodile). Phytosaurs were long-snouted and heavily armoured, bearing
11439-501: The size grew larger and the toes reduced, the teeth changed from those of a browser to those of a grazer. All such changes could be explained by a general alteration in habitat from forest to grassland. And, it is now known, that is what did happen over large areas of North America from the Eocene to the Pleistocene : The ultimate causative agent was global temperature reduction (see Paleocene–Eocene Thermal Maximum ). The modern account of
11562-547: The so-called "alligator dances". In summer, the female builds a nest of vegetation where the decomposition of the vegetation provides the heat needed to incubate the eggs. The sex of the offspring is determined by the temperature in the nest and is fixed within seven to 21 days of the start of incubation. Incubation temperatures of 30 °C (86 °F) or lower produce a clutch of females; those of 34 °C (93 °F) or higher produce entirely males. Nests constructed on leaves are hotter than those constructed on wet marsh, so
11685-460: The southernmost regions are they rare, possibly due to increased aridity. A somewhat more advanced and larger form, Angistorhinus appears at the same time or soon after. Later in the Carnian, both these animals were replaced by more specialised forms like Rutiodon , Leptosuchus , and the huge Smilosuchus (Lucas 1998). The Carnian-Norian extinction meant that these animals died off, and
11808-455: The surviving story of the debate is a later fabrication. Huxley had been planning to leave Oxford on the previous day, but, after an encounter with Robert Chambers , the author of Vestiges , he changed his mind and decided to join the debate. Wilberforce was coached by Richard Owen , against whom Huxley also debated about whether humans were closely related to apes. Huxley was slow to accept some of Darwin's ideas, such as gradualism , and
11931-478: The traditional beliefs of organised religion made enemies in the establishment – he had vigorous debates in print with Benjamin Disraeli , William Ewart Gladstone , and Arthur Balfour , and his relationship with Lord Salisbury was less than tranquil. Huxley was for about thirty years evolution's most effective advocate, and for some Huxley was " the premier advocate of science in the nineteenth century [for]
12054-400: The water to drink. Altirostral ("high snouted") animals are intermediate between the two distinct types. They had heterodont dentition but not as extremely developed as the brachyrostral type. Pseudopalatus is an altirostral phytosaur, and was most likely a generalist feeder. Modern crocodilians exhibit a similar morphological diversity, for example the broad snouted altirostral alligator and
12177-410: The water, and occurred in marine environments. A skeleton of Mystriosuchus planirostris , found in a marine setting and with evidence of little post-mortem transportation – indicating that it died either at sea or in a freshwater environment nearby – shows that this animal had paddle-like limbs, less adapted for terrestrial locomotion than in most other phytosaurs. Furthermore, the tail of Mystriosuchus
12300-469: The wetlands, they increase plant diversity and provide habitat for other animals during droughts. They are, therefore, considered an important species for maintaining ecological diversity in wetlands. Farther west, in Louisiana, heavy grazing by nutrias and muskrats is causing severe damage to coastal wetlands. Large alligators feed extensively on nutrias, and provide a vital ecological service by reducing nutria numbers. The Chinese alligator currently
12423-452: The whole English-speaking world". Though he had many admirers and disciples, his retirement and later death left British zoology somewhat bereft of leadership. He had, directly or indirectly, guided the careers and appointments of the next generation. Huxley thought he was "the only man who can carry out my work": The deaths of Balfour and W.K. Clifford were "the greatest losses to science in our time". The first half of Huxley's career as
12546-431: The young alligators. Alligators, much like birds, have been shown to exhibit unidirectional movement of air through their lungs. Most other amniotes are believed to exhibit bidirectional, or tidal breathing. For a tidal breathing animal, such as a mammal, air flows into and out of the lungs through branching bronchi which terminate in small dead-end chambers called alveoli . As the alveoli represent dead-ends to flow,
12669-605: Was "deep in debt". So, at a friend's suggestion, he applied for an appointment in the Royal Navy . He had references on character and certificates showing the time spent on his apprenticeship and on requirements such as dissection and pharmacy. William Burnett , the Physician General of the Navy, interviewed him and arranged for the College of Surgeons to test his competence (by means of a viva voce ). Finally, Huxley
12792-477: Was America's first professor of palaeontology, but also one who had come west into hostile Indian territory in search of fossils, hunted buffalo, and met Red Cloud (in 1874). Funded by his uncle George Peabody , Marsh had made some remarkable discoveries: the huge Cretaceous aquatic bird Hesperornis , and the dinosaur footprints along the Connecticut River were worth the trip by themselves, but
12915-426: Was a Secretary of the Royal Society and from 1883 to 1885 he was president. He was president of the Geological Society from 1868 to 1870. In 1870, he was president of the British Association at Liverpool and, in the same year was elected a member of the newly constituted London School Board . He was president of the Quekett Microscopical Club from 1877 to 1879. He was the leading person amongst those who reformed
13038-731: Was able to summarise this work in The Oceanic Hydrozoa , published by the Ray Society in 1859. The value of Huxley's work was recognised and, on returning to England in 1850, he was elected a Fellow of the Royal Society. In the following year, at the age of twenty-six, he not only received the Royal Society Medal but was also elected to the Council. He met Joseph Dalton Hooker and John Tyndall , who remained his lifelong friends. The Admiralty retained him as
13161-409: Was an English biologist and anthropologist who specialized in comparative anatomy . He has become known as " Darwin's Bulldog " for his advocacy of Charles Darwin 's theory of evolution . The stories regarding Huxley's famous 1860 Oxford evolution debate with Samuel Wilberforce were a key moment in the wider acceptance of evolution and in his own career, although some historians think that
13284-532: Was arranged by Edward Forbes FRS (who had also been a pupil of Knox). Both before and after the voyage Forbes was something of a mentor to Huxley. Huxley's paper "On the anatomy and the affinities of the family of Medusae" was published in 1849 by the Royal Society in its Philosophical Transactions . Huxley united the Hydroid and Sertularian polyps with the Medusae to form a class to which he subsequently gave
13407-464: Was chaired by Darwin's former botany tutor John Stevens Henslow . Darwin's theory was opposed by the Bishop of Oxford, Samuel Wilberforce , and those supporting Darwin included Huxley and their mutual friends Hooker and Lubbock . The platform featured Brodie and Professor Beale, and Robert FitzRoy , who had been captain of HMS Beagle during Darwin's voyage, spoke against Darwin. Wilberforce had
13530-427: Was descended from an ape on his mother's side or his father's side) was probably unplanned, and certainly unwise. Huxley's reply to the effect that he would rather be descended from an ape than a man who misused his great talents to suppress debate—the exact wording is not certain—was widely recounted in pamphlets and a spoof play. The letters of Alfred Newton include one to his brother giving an eyewitness account of
13653-399: Was determined to educate himself. He became one of the great autodidacts of the nineteenth century. At first he read Thomas Carlyle , James Hutton 's Geology , and Hamilton 's Logic . In his teens, he taught himself German , eventually becoming fluent and used by Charles Darwin as a translator of scientific material in German. He learned Latin , and enough Greek to read Aristotle in
13776-424: Was enough for Huxley to give credence to Darwin's gradualism, and to introduce the story of the horse into his lecture series. Marsh's and Huxley's conclusions were initially quite different. However, Marsh carefully showed Huxley his complete sequence of fossils. As Marsh put it, Huxley "then informed me that all this was new to him and that my facts demonstrated the evolution of the horse beyond question, and for
13899-407: Was exonerated of crime, but thought it best to leave Scotland. In 1845, under Wharton Jones' guidance, Huxley published his first scientific paper demonstrating the existence of a hitherto unrecognised layer in the inner sheath of hairs, a layer that has been known since as Huxley's layer . Later in life, Huxley organised a pension for his old mentor. At twenty he passed his First M.B. examination at
14022-552: Was extended in the early 1870s to include a large drawing and dining room at which he held informal Sunday gatherings. In 1890, he moved from London to Eastbourne , where he had purchased land in the Staveley Road upon which a house was built, 'Hodeslea', under the supervision of his son-in-law F. Waller. Here Huxley edited the nine volumes of his Collected Essays . In 1894 he heard of Eugene Dubois ' discovery in Java of
14145-504: Was in London's Rotherhithe amidst the squalor endured by the Dickensian poor. Afterward, another brother-in-law took him on: John Salt, his eldest sister's husband. Now aged 16, Huxley entered Sydenham College (behind University College Hospital ), a cut-price anatomy school. All this time Huxley continued his programme of reading, which more than made up for his lack of formal schooling. A year later, buoyed by excellent results and
14268-501: Was in his 80s and possibly the oldest alligator living in captivity. Alligators are native only to the United States and China . American alligators are found in the southeast United States : all of Florida and Louisiana ; the southern parts of Georgia , Alabama , and Mississippi ; coastal South and North Carolina ; East Texas , the southeast corner of Oklahoma , and the southern tip of Arkansas . Louisiana has
14391-411: Was laterally compressed and could have been used in propulsion. Scans on various phytosaur braincases suggest that these animals generally had long olfactory tracts, weakly demarcated cerebral regions, dorsoventrally short endosseous labyrinths and various sinuses, including large antorbital and dural venous ones; the general bauplan is vaguely similar to that of crocodilians, but differs significantly in
14514-433: Was made Assistant Surgeon ('surgeon's mate', but in practice marine naturalist) to HMS Rattlesnake , about to set sail on a voyage of discovery and surveying to New Guinea and Australia. The Rattlesnake left England on 3 December 1846 and, once it arrived in the southern hemisphere, Huxley devoted his time to the study of marine invertebrates. He began to send details of his discoveries back to England, where publication
14637-402: Was presented by Lyell and Hooker to the Linnean Society in 1858 alongside excerpts from Darwin's notebook and a Darwin letter to Asa Gray . Huxley's famous response to the idea of natural selection was "How extremely stupid not to have thought of that!" However, he never conclusively made up his mind about whether natural selection was the main method for evolution, though he did admit it was
14760-490: Was the kind of thing Darwin did with his closest scientific friends, but he must have had some particular intuition about Huxley, who was by all accounts a most impressive person even as a young man. Huxley was therefore one of the small group who knew about Darwin's ideas before they were published (the group included Joseph Dalton Hooker and Charles Lyell ). The first publication by Darwin of his ideas came when Wallace sent Darwin his famous paper on natural selection, which
14883-434: Was undecided about natural selection , but despite this, he was wholehearted in his public support of Darwin. Instrumental in developing scientific education in Britain, he fought against the more extreme versions of religious tradition. Huxley coined the term " agnosticism " in 1869 and elaborated on it in 1889 to frame the nature of claims in terms of what is knowable and what is not. Huxley had little formal schooling and
15006-426: Was virtually self-taught. He became perhaps the finest comparative anatomist of the later 19th century. He worked on invertebrates , clarifying relationships between groups previously little understood. Later, he worked on vertebrates , especially on the relationship between apes and humans. After comparing Archaeopteryx with Compsognathus , he concluded that birds evolved from small carnivorous dinosaurs ,
15129-513: Was wrong to pitch the loss of orders in the Phanerozoic as low as 7%, and he did not estimate the number of new orders which evolved. Persistent types sat rather uncomfortably next to Darwin's more fluid ideas; despite his intelligence, it took Huxley a surprisingly long time to appreciate some of the implications of evolution. However, gradually Huxley moved away from this conservative style of thinking as his understanding of palaeontology, and
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